JP4360175B2 - Ultrasonic transmission / reception array sensor, ultrasonic flaw detector, and ultrasonic flaw detection method therefor - Google Patents

Description

  The present invention relates to an ultrasonic inspection apparatus, and more particularly, to an ultrasonic inspection apparatus and an inspection method for performing inspection of a material to be inspected using ultrasonic waves by an ultrasonic transmission / reception array sensor attached to a self-running mobile body. .

Two probes, an ultrasonic transmission probe and a reception probe, are fixedly arranged at regular intervals.
There is a device for ultrasonic flaw detection in a body to be inspected using the (Time of F1ight. Diffraction) method, and the specification of the TOFD method is specified in the British standard BS 7706 (1993). In addition, in the TOFD method, the incident angle at which the ultrasonic wave emitted from the transmitting probe is incident on the object to be inspected is 45 degrees to 55 degrees, and the diffracted wave from the defect tip in the inspection object based on the ultrasonic wave is received. It is known that the reception angle received by the probe is also set to 45 to 55 degrees (see, for example, Patent Document 1).

  On the other hand, since the intensity of the diffracted wave is reduced due to the spread of the transmitted ultrasonic wave and there is a concern about the decrease in defect detectability, the ultrasonic wave emitted from the transmission probe can be used as a method to eliminate the concern. It is known to focus and irradiate the tip of the defect and also to detect the diffracted wave efficiently by focusing the diffracted wave detection area of the receiving probe (see, for example, Patent Document 1 and Patent Document 2). .

  In the case of efficiently detecting the diffracted wave, it is known that the incident angle of the ultrasonic wave is preferably 45 degrees from the viewpoint of efficiency (see, for example, pages 4 to 5 of Patent Document 2 and FIG. 2).

  Furthermore, a transducer group in which a plurality of transducer elements are assembled is used as a transmission transducer array and a reception transducer array equipped in the same casing, and a delay circuit is provided for each transducer element of the transducer group. Defect depth measurement by finely adjusting the refraction angle of the ultrasonic wave by electronic scanning while controlling the direction of ultrasonic wave propagation by gradually shifting the excitation timing of each vibration element by the delay circuit (See, for example, pages 3 to 6 and FIGS. 1 to 12 of Patent Document 3).

An inspection apparatus for a shroud, which is a reactor internal structure, will be described. In the periodic inspection of nuclear reactors, the inspection range and inspection method are JEAC4205, and the ultrasonic inspection is JEAG.
It is defined by the standard 4207. Standards are currently being prepared for in-furnace structures such as shrouds. For this reason, when performing ultrasonic inspection of in-furnace structures for the time being, it is performed in accordance with JEAG 4207, which is a standard for periodic inspection. JEAG4207 stipulates that the vertical method and the oblique angle method are performed as flaw detection methods, respectively, and that the oblique angle method is 45 degrees and 60 degrees, or that the difference between the two angles is at least 10 degrees or more. As shown in FIG. 2, the probe 31 is also scanned so that the ultrasonic wave 16 propagates in a direction orthogonal to and parallel to the weld line 32, and the probe 31 is moved in a direction orthogonal to the weld line 32. When scanning, the probe 31 is scanned from both sides of the weld line 32 in a direction parallel to the weld line 32. When scanning the probe 31 from both directions, the ultrasonic waves are applied to the weld line 32 in four directions. 16 is specified to propagate.

  The following devices have been invented as self-propelled ultrasonic inspection apparatuses for performing ultrasonic inspection of furnace internals. This self-propelled ultrasonic inspection device is provided with a seal skirt that contacts the wall surface at the ventral side opening, and water inside the device is discharged by a thrust fan provided on the back side of the device main body, keeping the inside of the device main body at a negative pressure. A moving mechanism is provided that adsorbs to the wall surface and moves the apparatus main body along the wall surface in the adsorbed state. Further, an ultrasonic inspection unit is attached to a probe scanner outside the main body of the apparatus, and ultrasonic inspection is performed (for example, see Patent Document 4).

JP 2001-228128 A (page 2-4, FIG. 1 to FIG. 8) Japanese Patent Laid-Open No. 2001-228126 (page 4 to page 5, FIGS. 1 to 4) Japanese Patent Application Laid-Open No. 2002-62281 (FIGS. 3-6 and 1-12) JP-A-9-95925 (page 2-9, FIG. 1 to FIG. 10)

A TOFD (Timer) in which two probes, an ultrasonic transmission probe and a reception probe, are fixed at regular intervals.
In the case of performing ultrasonic flaw detection by the method of Flight Diffraction (Flight Time of Flight Diffraction), the incident angle of the ultrasonic wave was set to 45 degrees to 55 degrees, and the reception angle was set to 45 degrees to 55 degrees. This angle is 45 degrees
The reason why it is defined as 55 degrees is that, conventionally, a diffracted wave obtained by irradiating ultrasonic waves on the tip of a defect has been generally used because it is considered that the direction of 45 degrees to 55 degrees is strong.

However, in the TOFD method in which the incident angle of the ultrasonic wave is set to about 45 to 55 degrees and the reception angle is set to about 45 to 55 degrees, the ultrasonic transmission probe and the reception probe are set to about 45 to 55 degrees. In order to maintain the transmission / reception angle, the distance between the ultrasonic transmission probe and the reception probe is fixed at a wide fixed interval according to it, and the outer dimensions of the ultrasonic transmission probe and the reception probe are combined. Because of its large size, it cannot be applied to the ultrasonic flaw detection of small inspection areas and narrow areas where each transducer is in contact, and the ultrasonic path length from transmission to reception of ultrasonic waves becomes longer. There was a problem that the sound wave reception intensity was weakened.

  Regarding the self-propelled inspection device, when the shroud is inspected by a method based on JEAG4207, it is necessary to run the ultrasonic inspection device so as to propagate ultrasonic waves in four directions with respect to the weld line. As shown in FIG. 3, when the probe for oblique angles 31 of the ultrasonic flaw detection unit 26 is a set, and the ultrasonic flaw detection unit 26 has no movable part driven by a motor, the ultrasonic wave is detected with respect to the welding line 32. Inspection is performed by changing the posture of the self-propelled ultrasonic inspection device 25 in each of the four directions in which 16 is propagated. Although it is possible to change the posture by turning the self-propelled ultrasonic inspection device 25 while adsorbing it to the wall surface, it is difficult to position, so that the self-propelled ultrasonic inspection device 25 is changed to the target posture. Takes time. Therefore, in order to inspect the weld line 32 without changing the posture of the self-propelled ultrasonic inspection apparatus 25, as shown in FIG. 4, the ultrasonic inspection unit 26 is provided with a rotating shaft 30, and the ultrasonic wave 16 is transmitted to the weld line. A method of changing the direction of propagation to 32 and a method of providing four sets of oblique angle probes 31 in the ultrasonic flaw detection unit 26 and propagating the ultrasonic wave 16 in four directions simultaneously with respect to the welding line 32 are conceivable. (Not shown). When the rotary shaft 30 is provided, the drive shaft of the apparatus main body is increased by one axis, and the probe scanner 27 becomes large. The self-propelled ultrasonic inspection apparatus 25 travels four times with respect to the same weld line 32, so that the inspection time is increased. There are problems such as lengthening.

  Further, when four sets of oblique angle probes 31 are provided in the ultrasonic flaw detection unit 26, the self-propelled ultrasonic inspection apparatus 25 only needs to run once with respect to the weld line 32, but the probe scanner 27 is large. As a result, the self-propelled ultrasonic inspection apparatus 25 becomes heavier, the output of the motor necessary for adsorbing to the wall surface increases, and the self-propelled ultrasonic inspection apparatus 25 also increases.

  Accordingly, an object of the present invention is to provide an ultrasonic inspection apparatus and method that are as small as possible, highly sensitive, and rapid.

An ultrasonic inspection apparatus for solving the above-described problems includes a transmission transducer array in which a plurality of transmission vibration elements for transmitting ultrasonic waves are arranged, and a reception in which a plurality of reception vibration elements for receiving ultrasonic waves are arranged. A transmission / reception array sensor in which both of the transducer arrays are connected in series in the arrangement direction of a plurality of elements, and each of the transmission vibrations at a focusing position where half of the sum of the ultrasonic transmission angle and the ultrasonic reception angle is within 30 degrees. each ultrasonic wave transmitted from the moving element is focused, the focused position of the ultrasonic wave transmitted from the moving element vibration for said transmission, said transmission oscillator column and the receiving transducer column of the check object in the material from the center of A control device that focuses and scans in the direction of the deep layer, and flaw detection based on the focused position of the transmitted ultrasonic wave, the ultrasonic information diffracted in the inspection target material received by the receiving vibration element Combining means for combining as information, and the combining An ultrasonic inspection apparatus having a display means for displaying the inspection information generated by the step.

Similarly, the ultrasonic inspection method includes a plurality of transmitting transducer arrays in which a plurality of transmitting transducer elements for transmitting ultrasonic waves are arranged and a receiving transducer array in which a plurality of receiving transducer elements for receiving ultrasonic waves are arranged. A transmitting / receiving array sensor coupled in series in the array direction is attached to self-running means that runs along the weld line via a scanning means, and the self-running means repeats running and stopping along the weld line. When the running means is stopped, the transmission / reception array sensor is passed over the welding line and mechanically scanned in a direction perpendicular to the welding line, and the sum of the ultrasonic transmission angle and the ultrasonic reception angle of the transmission / reception array sensor is calculated. half vibration said focus the respective ultrasonic waves that are transmitted from the moving element vibration for each of the transmission in the deep portion direction of the examination-target material in which the weld line is applied received the focusing position is within 30 degrees The inspection received by the element Ultrasound information that has been diffracted by the elephants material as synthesized as inspection information based on the focusing position of the transmission ultrasonic wave is an ultrasonic inspection method.

  In the case of sizing surface defects, the transmission / reception array sensor is installed perpendicular to the crack length direction of the surface defects. The position of the crack is detected by an eddy current flaw detection sensor provided for the ultrasonic transducer, and the ultrasonic wave is controlled so that a crack of a surface defect comes directly under the joint surface of the transmitting transducer array and the receiving transducer array. This is an ultrasonic inspection method for flaw detection.

  According to the present invention, the number of probes and the drive shaft of the probe scanner can be minimized, the traveling main body of the ultrasonic inspection apparatus can be miniaturized, and the ultrasonic inspection period can be shortened. .

  In an embodiment of the present invention, an ultrasonic inspection apparatus that uses an ultrasonic wave to detect a material to be inspected by using an ultrasonic transmission / reception array sensor mounted on a self-running traveling body, an ultra-small and highly sensitive ultrasonic inspection apparatus is used. In order to provide an ultrasonic inspection apparatus, a transmission vibrator array 15 in which a plurality of transmission vibration elements for transmitting ultrasonic waves are arranged, and a reception vibrator array 19 in which a plurality of reception vibration elements for receiving ultrasonic waves are arranged. The transmitting / receiving array sensor 14 having both is mounted on a self-running means that runs along the weld line via a scanning means, and the self-running means is repeatedly run and stopped along the weld line so as to perform the self-running. When the apparatus is stopped, the transmission / reception array sensor 14 is mechanically scanned in a direction perpendicular to the weld line through the weld line, and the ultrasonic transmission / reception angles are set to 0 to 90 degrees, respectively. Is said sending A half of the sum of the ultrasonic transmission angle and the ultrasonic reception angle of the signal array sensor 14 is preferably set to be within 30 degrees, and the ultrasonic wave is transmitted to each of the transmission focal points within the set range. Each ultrasonic wave 16 transmitted from the vibration element is focused and flaw detection information is generated based on the ultrasonic wave received by the reception vibration element, and the flaw detection information is visualized on the display device 6.

  The inventors have an array type transmission ultrasonic transducer (also referred to as a transmission array sensor) having a transmission transducer array in which a plurality of ultrasonic transducer elements are arranged, and reception in which a plurality of ultrasonic transducer elements are arranged. A transmission / reception integrated small array sensor (hereinafter simply referred to as a transmission / reception array sensor or sensor) in which an array type transmission / reception ultrasonic transducer (also referred to as a reception array sensor) having a transducer array is housed in one casing and is integrally molded. For short). The inventors focused on both the transmission and reception of ultrasonic waves using this sensor, and set the transmission / reception angles of ultrasonic waves that were conventionally considered difficult to detect diffracted waves to 0 respectively. Defect inspection and defect sizing test were performed by irradiating the ultrasonic wave to the defect in the inspection object with the angle set to 90 ° to 90 °.

  As a result, the inventors made it clear for the first time that defect inspection and defect sizing can be carried out satisfactorily. That is, a new ultrasonic flaw detection method different from the conventional TOFD method in which the ultrasonic transmission / reception angle is 45 to 55 degrees could be established. This new ultrasonic flaw detection method can widen the crossing region of the transmission and reception focusing points, and the detection sensitivity fluctuates due to a slight misalignment between the transmission ultrasound focusing point and the reception ultrasound focusing point. As a result, a so-called robustness of defect detection sensitivity, that is, a feature capable of stably performing defect detection and defect sizing can be realized.

  Using this new ultrasonic flaw detection method, defect detection and defect sizing were impossible with the conventional end echo method and TOFD method. (1) Narrow defect width and weak ultrasonic diffraction intensity Defects, (2) Defects in materials with large ultrasonic attenuation and anisotropic materials in which ultrasonic waves bend, (3) Defects in inspection areas and narrow areas where the probe contactable area is small, (4) Welding Defect detection and defect sizing of defects in metal could be realized.

  Further, as will be described later, since this new ultrasonic flaw detection method can detect flaws existing directly under the sensor 14, ultrasonic measurement from four directions is unnecessary as described above with reference to FIG. Since it is a flaw detection method, it suffices to scan just above the point to be flawed, so that the measurement time can be reduced to about a quarter, so that rapid defect sizing can be realized.

  A specific embodiment for realizing this new ultrasonic flaw detection method will be described below. FIG. 1 shows the entire ultrasonic flaw detector according to the present invention. The ultrasonic flaw detector according to the embodiment of the present invention is roughly divided into an ultrasonic flaw detector main body 122, and a transmission / reception array sensor 14 (hereinafter simply referred to as a sensor) electrically connected to the ultrasonic flaw detector main body 122 through signal lines. 14). Each signal line is bundled to form a signal cable 123.

  The sensor 14 transmits ultrasonic waves 16 from the respective vibration elements A, B, C, and D of the transmission transducer array 15 constituting the transmission array sensor into the inspection target material 21 that is the inspection target. The diffracted waves generated by diffracting the ultrasonic wave 16 at the lower end of the defect 22 in the inspection object material 21 based on the above are obtained by the respective vibrating elements O, P, Q, and R of the receiving transducer array 19 constituting the receiving array sensor. The electrical signal generated in each vibration element by receiving and receiving the diffracted wave from each vibration element of the reception transducer array 19 is output to the ultrasonic flaw detector main body 122. Since the vibration elements A, B, C, and D of the transmission vibrator array 15 are used for transmission, they are transmission vibration elements, and the vibration elements O, P, Q, and R of the reception vibrator array 19 are for reception. It can be defined as a receiving vibration element.

  The sensor 14 including the transmission transducer array 15 and the reception transducer array 19 is placed on the surface of the inspection target material 21 so that the central portion of the sensor 14 is positioned directly above the defect 22.

  The ultrasonic flaw detector main body 122 receives an electrical signal from each vibration element of the receiving transducer array 19 and creates an inspection result as an ultrasonic flaw detection result. As the ultrasonic flaw detector main body 122, the input device 1, the memory 2, the ultrasonic control device 3, the information processing device 4, the I / O 5, the display device 6, the transmission side amplifier control device 9, the reception side amplifier control device 10, and the transmission. The ultrasonic transducer control device 7, the reception signal processing device 8, the transmission side amplifier 11, and the reception side amplifier 12 are included.

  In the following, a detailed description of each of these devices and the role of that device will be described. FIG. 1 shows an overall view of an ultrasonic flaw detector according to an embodiment of the present invention. FIG. 5 describes a flow of operation steps in the embodiment of the present invention.

  First, input conditions for determining an ultrasonic transmission / reception pattern are input using the input device 1 (step a). The input condition is a condition for determining an ultrasonic wave transmission / reception pattern for detecting a defect with high sensitivity. (1) Vibration elements A, B, C, D, (2) Vibration elements O, P, Q, R of the reception transducer array, (3) positions of transmission ultrasonic focusing points (F11, F12,..., Fmn, m = 1 to i, n = 1 to j), (4) The position of the receiving-side focusing point (F11, F12,..., Fmn, m = 1 to i, n = 1 to j), (5) a gain representing the amplification degree of the transmitting-side amplifier 11, and (6) the receiving-side amplifier 12 It consists of a gain representing the degree of amplification. This input condition is transferred from the input device 1 to the memory 2 and the ultrasonic control device 3 (step b).

  The ultrasonic control device 3 calculates the ultrasonic transmission timing Ttimn and the reception timing Trimn of each ultrasonic transducer such that the ultrasonic wave is focused on each ultrasonic focusing point based on the input conditions (step c). Here, Tt: transmission ultrasonic delay time, Tr: reception delay time, i: vibration element number (A, B, C,...), Mn: two-dimensional coordinates.

  Transmitting ultrasonic transducer control device 7 transmits ultrasonic control signals necessary for operating the vibrating elements A, B, C, D of the transmitting transducer array and the vibrating elements O, P, Q, R of the receiving transducer array. And it transmits to the received signal processing device 8 from the ultrasonic control device 3 via the I / O 5 (step d). The transmission ultrasonic transducer control signal (focusing point Fmn, initial value F11) is amplified using the transmission-side amplifier 11 and supplied to each vibration element A, B, C, D of the transmission transducer array 15 (step e). ).

Each ultrasonic wave 16 emitted from each vibration element A, B, C, D of the transmission vibrator array 15.
Since the (spherical wave) has a time difference, each ultrasonic wave 16 is focused at the position of the focusing point 17 (Fmn) inside the inspection target material 21 (step f). In FIG. 1, in order to focus the ultrasonic wave 16 on the focusing point 17 (Fmn), a transmission signal to the vibration element A existing near the outermost part of the sensor 14 farthest from the focusing point 17 (Fmn) is input earliest. The earliest ultrasonic wave is emitted from the vibration element A. Further, the transmission signal to the vibration element D existing near the center of the sensor 14 closest to the focusing point 17 (Fmn) is input the latest, and the ultrasonic wave 16 is emitted from the vibration element D the latest.

  FIG. 6 shows a timing chart of the transmission ultrasonic transducer control signal to each vibration element. FIG. 7 shows a generation timing chart of the ultrasonic wave 16 generated in FIG. As described above, the delay times TtAmn, TtBAmn, TtCmn,... To the vibrating elements A, B, C, D for focusing the ultrasonic waves at the position of the focusing point 17 (Fmn) inside the inspection target material 21. Is calculated by the ultrasonic control device 3. Accordingly, since the ultrasonic wave 16 (spherical wave) has a time difference, the ultrasonic wave can be focused at the position of the focusing point 17 (Fmn) inside the inspection target material 21.

  When there is a defect end at the position of the focusing point 17 (Fmn), the ultrasonic wave is diffracted at the defect end to generate a diffracted wave 18, and the diffracted wave 18 is generated by each vibration element O, P, Q of the receiving transducer array 19. , R are incident with a time difference (step g).

  In FIG. 1, the diffracted wave 18 incident on the receiving-side vibrating element O existing near the center of the sensor 14 closest to the focusing point 17 (Fmn) is the earliest in time and the farthest from the focusing point 17 (Fmn). The diffracted wave 18 incident on the receiving-side vibrating element R existing near the outermost part of the sensor 14 is the slowest in time. When the diffracted wave 18 is incident on the vibration elements O, P, Q, and R of the reception transducer array 19, the intensity and time of the diffracted wave 18 are applied to the vibration elements O, P, Q, and R of the reception transducer array 19. A corresponding ultrasonic reception signal (electrical signal) is induced, and this ultrasonic reception signal (electrical signal) is amplified by the reception side amplifier 12 and input to the reception signal processing device 8 (step h) (where, The reception-side amplifier 12 and the reception signal processing device 8 may be interchanged, and the reception signal processing device 8 may add the signals and synthesize them into one signal, and then amplify with one reception-side amplifier 12).

  In the reception signal processing device 8, the reception focusing point 17 (Fmn) of each vibration element O, P, Q, R of the reception vibrator array 19 and each vibration element O, P, Q, R of the reception vibrator array 19 are set. After controlling the reception timing Trimn for synthesizing each ultrasonic reception signal (electrical signal) from the positional relationship (distance relationship), each ultrasonic reception signal (electrical signal) is added to create one ultrasonic reception signal ( Step i). As for the reception timing Trimn, the reception focus points of the respective vibration elements O, P, Q, and R of the reception transducer array 19 are focused on the reception focus point (same as the focus point 17 (Fmn)) determined by the input conditions. Such a value is calculated by the ultrasonic control device 3.

  The ultrasonic reception signal is transferred to the information processing apparatus 4 and the memory 2 via the I / O 5 (step j). FIG. 8 shows a representative example when the ultrasonic reception signal obtained here is processed by the information processing device 4 according to the display form and displayed as flaw detection information on the display device 6. This signal display is called an A scope, and as flaw detection information, the horizontal axis indicates the time of the ultrasonic reception signal (electric signal), and the vertical axis indicates the ultrasonic reception signal intensity. By displaying the defect diffraction wave signal as flaw detection information as shown in FIG. 8, it is possible to detect the defect by recognizing the existence of the defect diffraction wave signal as the existence basis of the defect. Further, the depth of the defect can be measured (defect sizing) based on the transmission time of the ultrasonic wave and the detection time of the diffracted wave (the propagation time of the ultrasonic wave).

  Since the diffracted wave 18 by the conventional ultrasonic flaw detection method is weak, in this embodiment, as described above, the transmission ultrasonic wave is focused on the defect end and the reception side is also focused, thereby greatly increasing the diffracted wave detection sensitivity. It becomes possible to improve. Moreover, by making the transmission angle of ultrasonic waves and the reception angle of diffracted waves variable from 0 to 90 degrees, it is possible to widen the intersection region of the transmission and reception focusing points, and to detect defects and detect defects. It became possible to make it robust. Thus, in the embodiment of the present invention, the ultrasonic transmission / reception angle is variable from 0 to 90 degrees, and at least one ultrasonic focusing point is set, and all the points may be set as such. .

  In this way, the ultrasonic control device 3 calculates the ultrasonic transmission timing and the reception timing so that the focal point of the ultrasonic wave 16 and the focal point of reception are in the same place, and transmits the control signal to the transmission ultrasonic transducer. This is given to the device 7 and the received signal processing device 8 for processing.

  The operations from step e to step j are performed when there are a plurality of focusing points (F11, F12,..., Fmn, m = 1 to i, n = 1 to j) defined by two-dimensional coordinates. By performing steps k, l, m, n, o after j, a plurality of focusing points are performed. Finally, the received signal obtained by receiving the diffracted wave in step P is processed by the information processing device 4 so as to match the desired display form, and the received signal is processed using the information processing device. An image is displayed on the display device 6 as flaw detection information in the display form, and information (received data) of the received signal is processed and analyzed.

As described above, in the embodiment of the present invention, in order to realize a flaw detection method that is small and has high sensitivity, high resolution, and robust defect detection, (1) in the ultrasonic flaw detection apparatus, the transmission array sensor and the reception array sensor There is an intersection (focusing point 17) of each focused sound field, and the intersecting point of the focused sound field is moved from 0 to 90 degrees by ½ of the sum of the transmission angle and reception angle of the ultrasonic wave formed by each. (2) The intersection of the focused sound fields is the center of the transmitting array sensor and the receiving array sensor,
(3) The values of the transmission angle θt and the reception angle θr of ultrasonic waves are also used in the region of 30 degrees or less, which has been considered difficult to detect diffracted waves in the past (the transmission angle θt and the reception angle θr are each 30 degrees or less). ), Transmit / receive ultrasonic waves to the defect, and carry out defect inspection and defect sizing test based on the propagation time of the ultrasonic wave. (4) Small size, high sensitivity, high resolution transmission / reception integrated type It can be proposed to use a small and dense array sensor (element width: 1.0 mm or less, insulation material width: 0.2 mm or less) suitable for a small array sensor.

FIG. 9 shows the definition of the transmission angle θt of the ultrasonic wave 16 from the sensor 14 to the inspection target material 21 and the reception angle θr of the diffracted wave 18 that is an ultrasonic wave to the sensor 14. The ultrasonic transmission angle θt is defined as an angle formed by a line (solid line in the figure) connecting the center of the transmission transducer array 15 and the converging point 17 and a center line (broken line in the figure) of the sensor 14. The reception angle θr is defined as an angle formed by a line (solid line in the figure) connecting the center of the reception transducer array 19 and the converging point 17 and a center line of the sensor 14 (broken line in the figure).

In the embodiment of the present invention, there is an intersection (focusing point 17) of each of the focused sound fields of the ultrasonic wave transmitted by the ultrasonic flaw detector and the ultrasonic wave received as the diffracted wave, and the ultrasonic wave with respect to the intersection of the focused sound field The intersection of the focused sound field is moved from 0 to 90 degrees, which is 1/2 of the sum of the transmission angle θt and the reception angle θr. In order to execute this operation, the transmission ultrasonic focusing point (F11) is used as an input condition so that the position of the intersection of the focused sound field is displaced when the values of the transmission angle θt and the reception angle θr are in the range of 0 to 90 degrees, respectively. , F12,..., Fmn, m = 1 to i, n = 1 to j) and the receiving-side focusing point (F11,
F12,..., Fmn, m = 1 to i, n = 1 to j) are input, and the operation flow of FIG.

  FIG. 10 shows the width / depth / height of the sensor 14, the vibration elements that convert an electrical signal into ultrasonic waves, that is, the element width / element length of the vibration elements that constitute the transmission transducer array 15 and the reception transducer array 19. The definition of thickness and insulation material width is illustrated.

In an embodiment of the present invention, a sensor 14 in which a transmitting array sensor and a receiving array sensor are integrated in a small size is used, and the size of the sensor 14 is larger than the width of a weld metal part that is an inspection target part or an inspection target part. It is small or equivalent, and the width of the vibration elements constituting the transmission transducer array 15 and the reception transducer array 19 provided in the sensor 14 is not less than 2 times and not more than 40 times the distance between the elements. In particular, in an ultrasonic flaw detector used in a nuclear reactor, the contact area (footprint) of a transmission / reception integrated small array sensor that directly contacts a weld metal part or a base material that is an inspection target surface is 30 mm in the width direction of the sensor 14. × As the sensor 14 is smaller than 30 mm in the depth direction, the defect can be detected or sized by directly contacting the sensor 14 from directly above the defect of the weld metal part. It was it is a feature. Regarding the vibration element of the sensor 14, if the element width exceeds 2.0 mm, the ultrasonic wave in the downward direction becomes strong right below and becomes weak in the horizontal direction, and as a result, it becomes difficult to control the focusing of the ultrasonic wave. When the element width is less than 0.1 mm, the vibration element width is 0.1 mm to 2.0 mm in consideration of the fact that the ultrasonic energy that can be transmitted becomes weak and the ultrasonic wave is not easily transmitted to a deep position. The width of the insulating material between the vibration elements was set to 0.05 mm to 0.2 mm. In this way, the small sensor 14 in which the vibration element is densified is configured.

  In the above description, the expression “the contact area of the transmission / reception integrated small array sensor that is in direct contact with the weld metal part or the base material to be inspected is a small size of 30 mm × 30 mm or less” is used. As a matter of course, a method of directly attaching the sensor 14 to the surface of the material to be inspected may be implemented by a partial water immersion method (water distance of 10 mm or less) used to avoid friction with the surface of the material to be inspected. Include as meaning.

  FIG. 11 shows an example of the structure of the sensor 14. Each transducer element of the transmission transducer array 15 and the reception transducer array 19 is installed on an epoxy resin plate 101 which is an entrance / exit surface through which ultrasonic waves enter and exit, and the position is fixed by the resin 102. A sound insulating material 103 that absorbs ultrasonic waves is filled between the casing 100 and the resin 102. In another example of the structure of the sensor 14 in FIG. 12, each transducer element of the transmission transducer array 15 and the reception transducer array 19 is installed on the epoxy resin plate 101, and a sound absorbing material 104 (cork material or the like) is interposed between them. As a result, the crosstalk of sound between the transmitting transducer array 15 and the receiving transducer array 19 can be greatly reduced, and noise can be reduced and detection sensitivity can be further improved.

  As will be described in detail in the embodiments described later, by using this apparatus configuration, it is possible to electronically scan the focusing point 17 in the direction directly below the center of the sensor 14, that is, to move the position of the focusing point 17. It becomes. FIG. 13 shows a representative example when a defect signal is displayed on the display device 6 as flaw detection information obtained here. In this signal display, the depth of the defect is displayed. The horizontal axis indicates the distance in the direction in which the transmitting transducer array 15 and the receiving transducer array 19 of the transmission / reception integrated small array sensor 14 are arranged, and the vertical axis indicates the sensor 14. The distance in the bottom direction. The origin in FIG. 13 is the center of the reception array probe, and the signal intensity at the ultrasonic reception angle θr centered on the origin (the signal intensity of the A scope is displayed as a color shading image) is displayed. That is, the gray level distribution on the two-dimensional coordinate represents the intensity of the ultrasonic reception signal (electric signal). Since it can be evaluated that there is a defect tip that is an ultrasonic wave generation source (reflection source) in a portion where the intensity of the ultrasonic reception signal (electric signal) is high, sizing of the defect is possible. As can be seen from FIG. 13, it is possible to visually recognize the tip of the defect, and the objectivity of defect detection and defect sizing can be improved.

  FIG. 14 shows another display example of the ultrasonic flaw detector according to the embodiment of the present invention. FIG. 14 shows an example in which there are two defect tips. A scope is displayed for each θr with respect to the focal depths F11 (θr = θ1), F12 (θr = θ2), F13 (θr = θ3), F14 (θr = θ4). FIG. 14 shows schematic waveforms of the A scope of F11 (θr = θ1), F12 (θr = θ2), F13 (θr = θ3), and F14 (θr = θ4). Focusing on F11 (θr = θ1), an ultrasonic signal existing in the ultrasonic focusing point region is considered as a defect indication signal, and similarly F12 (θr = θ2), F13 (θr = θ3), F14 (θr = θ4). Focusing on the ultrasonic focusing point area of (), if the ultrasonic focusing point area is gated and added together, the lowest A scope waveform (AC scope) is obtained. Since it can be recognized that there is a defect tip where the ultrasonic signal of the AC scope is present, defect detection and defect sizing are possible.

Under a flaw detection condition in which the focusing point 17 is electronically scanned in the direction directly below the center of the sensor 14, the sensor 14 is mechanically scanned (the transducer elements 15 of the sensor 14 and the transducer elements 19 of the receiver array 19 are arranged side by side). FIG. 15 shows a typical example when flaw detection information including a defect signal is displayed on the display device 6 in the case of scanning in a horizontal direction orthogonal to the direction in which it is present. The horizontal axis represents the time of the ultrasonic reception signal (electric signal), the vertical axis represents the distance in the scanning direction of the sensor 14, and the grayscale distribution on the two-dimensional coordinates represents the intensity of the ultrasonic reception signal (electric signal). is there. That is, it can be evaluated that there is a tip of a defect that is a generation source (reflection source) of an ultrasonic wave as a diffracted wave in a locally high intensity portion of the ultrasonic reception signal (electric signal), and other stationary Since a portion having a high intensity can be determined as a bottom echo, a defect can be detected and sized.

  Information on received signals obtained by transmitting and receiving ultrasonic waves is visualized on the display device 6 as flaw detection information by display in any one of FIGS. 13, 14, and 15. The flaw detection information is received by the received signal processing device. 8 is processed by the information processing device 4 into the flaw detection information in the display form based on the received signals sent to the memory 2 from the memory 8 and the received signals sent to the information processing device 4 and displayed on the display device 6. The

  In FIG. 1, the position of the tip of the lower side of the defect 22 is generally known, and the input condition is set so that the focal point 17 of the ultrasonic wave 16 is set to one place in accordance with the position of the tip. A focal point 17 of the ultrasonic wave 16 is determined at the tip of the defect 22 opened on the surface of the inspection target material 21 (the lower end of the defect 22 in each figure), and the ultrasonic wave 16 is transmitted to be focused on the focal point 17. The ultrasonic waves 16 are transmitted from the vibration elements A, B, C, and D of the transducer array 15 to focus the ultrasonic waves 16 toward the focusing point 17 that is the tip of the defect 22. The focused ultrasonic wave 16 is diffracted at the tip of the defect 22 to generate a diffracted wave 18. This diffracted wave 18 is received by being incident on each vibration element O, P, Q, R of the receiving transducer array 19. When each oscillating element O, P, Q, R receives the diffracted wave, an ultrasonic reception signal (electrical signal) is output from each oscillating element O, P, Q, R and transmitted to the transmission / reception signal delay control device 7. After the amplification and delay processing is executed, the waveform of FIG. 8 that is an ultrasonic waveform is displayed on the display device 6. The display content may be shown in FIG. 13, FIG. 14, or FIG. This enables defect detection and defect sizing. In FIG. 1, the method when the tip of the defect 22 is known to some extent by some other method is described. In this case, since there is only one focal point 17, there is no need to set a plurality of focal points 17 and move the focal point. However, in most cases, the tip position of an actual defect is unknown, and an ultrasonic flaw detection method in that case will be described below.

  FIG. 16 shows another example in which the ultrasonic flaw detector according to the embodiment of the present invention is applied to defect detection and defect sizing. In actual inspection, there is often only initial information that there is an opening of the defect 22 on the surface of the inspection target material 21 by visual inspection using a camera or the like. That is, the ultrasonic flaw detection test is often performed in a state where the depth of the defect 22, that is, the position of the lower end of the defect 22 is unknown. FIG. 16 describes an example in which an ultrasonic flaw detection test is performed in such a state that the depth of the defect 22 is unknown, which will be described in detail below.

  Defect flaw detection and sizing procedures will be described below with reference to FIG. The sensor 14 is pressed directly above the defect 22 generated in the inspection target material 21, that is, the opening of the defect 22 that appears on the surface of the inspection target material 21 so that the central portion of the sensor 14 faces.

  The alignment of the defect 22 and the sensor 14 is performed by visual observation or remote visual inspection using a camera and illumination, and the center of the sensor 14 and the opening of the defect 22 are aligned. That is, the position of the sensor 14 is aligned directly above the defect 22 to perform defect detection and defect sizing.

Since the depth of the defect 22 cannot be determined by visual observation from the opening side of the defect 22 existing on the surface of the inspection target material, in this embodiment, the focus point 17 (= the focus reception point of the ultrasonic wave) of the transmission ultrasonic wave 16 is set as the defect. Are continuously or discretely scanned in the direction directly below the sensor 14 which is the depth (depth) direction. Scanning of the focusing point 17 of the transmission ultrasonic wave 16 (= focusing reception point of the ultrasonic wave) directly below the sensor 14 controls the transmission ultrasonic transducer control device 7 and the reception signal processing device 8 using the ultrasonic control device 3. Since the ultrasonic focusing width has a finite size of several millimeters, the diffracted wave 18 is generated by the interaction between the end of the defect 22 and the focused transmission ultrasonic wave 16. The diffracted wave 18 is incident on the receiving transducer array 19, and the ultrasonic reception signal (electric signal) is amplified by the reception-side amplifier 12, transmitted / signal synthesized to the reception signal processing device 8, and stored in the memory 2 or information processing. Signal processing is performed by the device 4. FIG. 8 shows the ultrasonic waveform obtained here, and FIGS. 13 and 15 show the outputs of defect detection and defect sizing. This enables defect detection and defect sizing even when the depth of the defect 22 is unknown.

  An example of changing the gain of the transmission amplifier according to the position (depth) of the focusing point 17 will be described with reference to FIG. 16 and Table 1. In FIG. 16, the focusing point 17 is scanned in the order of F11 → F12 → F13 → F14. For this reason, in the example of FIG. 16, four positions are set as input conditions for determining the ultrasonic transmission / reception pattern as the positions of the transmission / reception focusing point 17.

In the vicinity of the inner surface layer (F11) of the focusing point 17 of the material to be inspected 21 (F11), the propagation distance of the ultrasonic wave is short compared to the deep point (F14), and the attenuation of the ultrasonic wave in the material to be inspected 21 is small. ) Has high ultrasonic intensity. On the other hand, the propagation distance of the ultrasonic wave is long at the point (F14) where the focusing point is deep, the attenuation of the ultrasonic wave in the inspection target material 21 is large, and the intensity of the ultrasonic wave is lower than that near the surface layer (F11). If the gain of the transmission-side amplifier 11 is set in accordance with the deep focus point (F14), the gain is too high in the vicinity of the surface layer (F11), and the dead zone of the ultrasonic wave becomes large. A defect near the surface layer (F11) cannot be detected.

For this reason, the gain of the transmission-side amplifier 11 is set lower in the vicinity of the surface layer (F11) of the material 21 to be inspected than in the point (F14) having a deep focal point. That is, in this embodiment, in order to give the optimum ultrasonic intensity to the focal point depth, the ultrasonic controller 3 calculates and sets the optimum ultrasonic intensity to the focal point depth, and controls the transmission side amplifier through the I / O 5. The apparatus 9 is controlled to change the gain of the transmission-side amplifier 11 according to the focal point depth. Therefore, the ultrasonic control device 3 and the transmission side amplifier control device 9 also function as a first amplification degree control device. This enables defect detection and defect sizing in a wide range from the vicinity of the inner surface layer (F11) of the focusing point 17 in the inspection target material 21 to the deep point (F14) of the focusing point.

  Table 1 shows typical gain settings of the transmission-side amplifier 11. AT1 to AT4 are amplifier names of the transmission side amplifier 11, and one amplifier is connected to one vibration element. F11 to F14 indicate transmission / reception focusing points 17, which are F11 to F14 in order from the shallowest focusing point 17. The gain at a focusing point (F11 to F14) of each amplifier AT1 to AT4 is G. For example, the gain of the convergence point F11 of the amplifier AT1 is GA1, and the gain of the convergence point F14 is GD1. As shown in Table 1, the gain of each amplifier is optimized according to the focal point depth, and the gain is set larger as the focal point depth becomes deeper (GA <GB <GC <GD). To do.

  In the above description, an example of the embodiment in which the gain of the transmission amplifier is changed according to the depth of the focusing point 17 has been described. However, this effect can also be realized by changing the gain of the receiving-side amplifier 12 according to the depth of the focusing point 17. One example will be described below. In the vicinity of the surface layer (F11) of the inspection target material 21, the ultrasonic propagation distance is short compared to the deep point (F14) and the attenuation of the ultrasonic wave in the inspection target material 21 is small. High strength. On the other hand, the propagation distance of the ultrasonic wave is long at the point (F14) where the focusing point is deep, the attenuation of the ultrasonic wave in the inspection target material 21 is large, and the intensity of the ultrasonic wave is lower than that near the surface layer (F11). If the gain of the receiving-side amplifier 12 is set in accordance with the deep point (F14) of the focusing point, the gain is too high in the vicinity of the surface layer (F11), and the defect in the vicinity of the surface layer (F11) of the inspection target material 21 is accurately detected. Cannot be detected.

For this reason, the gain of the receiving-side amplifier 12 is set to be lower in the vicinity of the surface layer (F11) of the material 21 to be inspected than in the deep point (F14) of the focusing point. That is, the feature of the present invention is to provide the optimum ultrasonic detection sensitivity to the focal point depth, so that the ultrasonic control device 3 calculates the optimum ultrasonic detection sensitivity to the focal point depth and sets the gain of the receiving-side amplifier 12. Then, the receiving side amplifier controller 10 is controlled through the I / O 5 to change the gain of the receiving side amplifier 12 in accordance with the focal point depth. Therefore, the ultrasonic control device 3 and the reception-side amplifier control device 10 also function as a second amplification degree control device.

As a result, it is possible to detect a defect from the vicinity of the surface layer (F11) of the material 21 to be inspected to the point (F14) having a deep focal point. Table 2 shows typical gain settings of the receiving amplifier 12. AR1 to AR4 are the names of the amplifiers of the receiving amplifier 12 in which one receiving-side amplifier 12 is connected to each vibrating element of the receiving transducer array. F11 to F14 indicate the focusing point 17; It is F11-F14 in order from a shallower one. The gain at a focusing point (F11 to F14) of each amplifier (AR1 to AR4) is G. For example, the gain of the focusing point F11 of the amplifier AR1 is GO1, and the gain of the focusing point F14 is GR1. As shown in Table 2, the gain of each amplifier is optimized according to the focal point depth, and the gain is set larger as the focal point depth becomes deeper (GO <GP <GQ <GR).

  In the above example, the gain of the transmission side amplifier or the reception side amplifier is changed according to the depth of the focusing point, but this effect changes the gains of both the transmission side amplifier and the reception side amplifier according to the focusing point (depth). This is also possible. That is, the gain of each amplifier of the transmission side amplifier and the reception side amplifier is optimized according to the depth of the focusing point 17, and the gain is set larger as the depth of the focusing point 17 becomes deeper. And

  FIG. 17 shows another example in which the ultrasonic flaw detector according to the embodiment of the present invention is applied to defect detection and defect sizing. As described above, in the example of FIG. 17, the defect detection and defect sizing method in the case where the defect 22 has progressed directly below the sensor 14 are described.

  As shown in FIG. 16, it is considered that there are many cases in which the defect 22 has progressed in the downward direction. However, as a rare case, the defect is not in the direct downward direction, and the defect that has progressed in the oblique direction or the tip of the defect is branched. It is also necessary to consider the cases that are present. FIG. 17 describes an example in which an ultrasonic flaw detection test is performed in a state where the progress shape of the defect is unknown, which will be described in detail below. Defect flaw detection and sizing procedures are described below. The sensor 14 is pressed directly above the surface opening of the defect 24 generated in the inspection target material 21 and extending in the oblique direction or the defect 24 where the defect tip branches.

Since the direction of defect propagation and the shape of the defect cannot be determined by visual inspection from the surface opening side, first, the focus point of the transmission ultrasonic wave 16 (= the focus reception point of the ultrasonic wave) is continuously or discretely below the sensor 14. After scanning and recording the ultrasonic data, the ultrasonic focusing of the focusing point (= the focused receiving point of the ultrasonic wave) is then performed in the vibration element array direction (X direction in FIG. 17) of the transmission transducer array 15 of the sensor 14. After moving a distance of about ½ or ¼ of the width (about several millimeters), the ultrasound data is recorded by scanning continuously or discretely in the downward direction (Y direction in FIG. 17).

  Thereafter, a focusing point (= focusing reception point of ultrasonic waves) is further set to 1 / of the ultrasonic focusing width (about several millimeters) in the vibration element array direction (X direction in FIG. 17) of the transmission transducer array 15 of the sensor 14. After moving a distance of about 2 or 1/4, the procedure of recording ultrasonic data by scanning continuously or discretely in the downward direction (Y direction in FIG. 17) is repeated. Two-dimensional scanning can be realized. Defect detection and defect sizing can be performed even for defects that have developed in the oblique direction and defects 24 with branched defect tips generated in the inspection target material 21 by the scanning method and defect detection of this embodiment.

So far, the method for detecting and sizing defects from the front surface opening side has been described. However, even when the defects shown in FIGS. 16 and 17 are detected from the back surface side by the same method, diffracted waves from the defect tip can be received. Needless to say, defect detection and sizing are possible. FIGS. 18 and 19 show an example in which the display device 6 displays a diffracted wave signal from the tip of the defect as flaw detection information when the defect is actually detected from the back side. 18 shows an example of flaw detection when the defect is orthogonal to the transmission / reception ultrasonic transducer group of the sensor 14, and FIG. 19 is an example of flaw detection when the defect is parallel to the transmission / reception ultrasonic transducer group. As described above, when a defect is detected by the sensor 14, the diffracted wave at the tip of the defect can be received even when the positional relationship between the transmission / reception ultrasonic transducer group of the sensor 14 and the defect is parallel or orthogonal. It turns out that it is possible. In other words, regardless of the position of the sensor 14 and the defect, if the focusing point of the sensor 14 can catch the tip of the defect, the defect can be detected and the defect sizing can be performed.

When the transmitting / receiving array sensor 14 according to the above-described embodiment is used for ultrasonic inspection in the vicinity of the weld line 33 of the shroud 41 installed in the water in the reactor pressure vessel, a self-propelled ultrasonic inspection as shown in FIG. Device 25 is used. The self-propelled ultrasonic inspection apparatus 25 has a traveling vehicle 40 that is employed as a self-propelled means.

The traveling vehicle 40 discharges water from the inside of the vehicle body 33 to the outside of the vehicle body 33 on the side opposite to the shroud 41 to a flat box-shaped vehicle body 33 having a surface opened on the shroud side, and the pressure in the vehicle body 33 is reduced. A thruster 34 ' that controls the negative pressure as compared with the outside pressure is provided. Further, a traveling motor 34 and wheels 35 that are rotationally driven by the traveling motor 34 are provided inside the vehicle body 32. Yes. The wheel 35 is in contact with the surface of the shroud 41 so that the vehicle body 33 is slightly lifted from the surface of the shroud 41. Control signals' power required to drive the motor and the travel motor 34 and thruster 34 'travel motor 34 and the thruster 34 can tell the supply and control command to travel from the remote location the motor 34 and thruster 34' through a cable.

  As shown in FIG. 20, a probe scanner 27 whose scanning degree of freedom is limited to a uniaxial direction is fixed to the end of the vehicle body 33 facing the inspection position. The probe scanner 27 has a drive shaft 36 and a guide shaft (in FIG. 20, the drive shaft and the guide shaft overlap with each other, and only the drive shaft is shown), and the drive shaft 36 has a screw. The guide shaft has a smooth outer surface. The drive shaft 36 and the guide shaft are passed through a moving frame 37 to which the ultrasonic flaw detection unit 26 is attached. The drive shaft 36 and its moving frame 37 are screwed together with screws, and the guide shaft and its moving frame 37 are slidably combined. The drive shaft 36 is connected to a scanning motor 38 that rotationally drives the drive shaft 36, and the power required for driving the scanning motor 38 and the control signal to the scanning motor 38 are used for scanning from a remote point through a cable. Supply and control commands can be transmitted to the motor 38.

The ultrasonic flaw detection unit 26 attached to the moving frame 37 includes the transmission / reception array sensor 14 according to the above-described embodiment and a probe holder 39 that supports the transmission / reception array sensor 14. The probe holder 39 is fixed to the moving frame 37. A suspension is provided so that the transmission / reception array sensor 14 can easily follow the surface of the shroud 31 between the transmission / reception array sensor 14 and the probe holder 39 or between the probe holder 39 and the moving frame 37. May be. The transmission / reception array sensor 14 is connected to the ultrasonic flaw detector main body 122 placed at a remote point by signal lines in the signal cable 123. The signal cable 123 may include a power supply cable for each motor and the thruster 34 ′ and a cable for transmitting a control signal.

  The self-propelled ultrasonic inspection apparatus 25 configured in this way is placed in water so as to cover the H4 weld line 32 of the intermediate cylinder of the shroud 41, and the thruster 35 'is driven to rotate to discharge water inside the vehicle body 33. Thus, the pressure closer to the shroud of the vehicle body 33 is maintained at a negative pressure than the surrounding pressure. Thus, in the state maintained at the negative pressure, the vehicle body 33 of the traveling vehicle 40 is not attracted to the surface of the shroud 41 and slips down. When the wheel 35 is rotationally driven by the traveling motor 34 in this state, the traveling vehicle 40 travels in parallel with the welding line 32 due to friction between the rotating wheel 35 and the surface of the shroud 41.

  When the traveling vehicle 40 reaches the inspection position, driving of the wheels by the traveling motor 34 is stopped and the vehicle is stopped. Thereafter, when the drive shaft 36 is rotationally driven by the scanning motor 38, the moving frame 37 is screwed by the screw of the drive shaft 36 to support the transmission / reception array sensor 14 in the direction perpendicular to the weld line 32 along the guide shaft. The probe holder 39 is scanned over the scanning range 28. Simultaneously with the scanning, as described in the above-described embodiment, ultrasonic waves are transmitted / received from the transmission / reception array sensor 14 to the focusing position in the shroud 41 where the half of the sum of the ultrasonic transmission angle and the ultrasonic reception angle is within 30 degrees. To do. At this time, as shown in FIGS. 16 and 17, the ultrasonic wave transmission / reception focusing position is electronically scanned in the depth direction of the thickness of the shroud.

  The ultrasonic reception result by the transmission / reception array sensor 14 is displayed on the display device 6 as described above. When defect information is included in the ultrasonic reception result by the transmission / reception array sensor 14, examples of display forms are as shown in FIGS.

  After the ultrasonic reception result by the transmission / reception array sensor 14 is obtained in the scanning range 28 at one inspection position, the traveling vehicle 40 stops the transmission / reception of the ultrasonic wave by the transmission / reception array sensor 14 and the traveling vehicle 40 in FIG. The traveling vehicle 40 is controlled so as to travel by one pitch 29 and stop again.

  Thereafter, the transmission / reception array sensor 14 is scanned again in the direction orthogonal to the weld line 32 over the scanning range 28, and at the same time, the ultrasonic transmission angle and the ultrasonic reception angle are transmitted from the transmission / reception array sensor 14 in the same manner as one pitch before. Ultrasonic waves are transmitted to and received from the focusing position in the shroud where half of the sum is within 30 degrees. At the same time, as shown in FIG. 16 and FIG. Scan also in the depth direction of the thickness of the shroud. Also in this case, the reception result of the ultrasonic wave by the transmission / reception array sensor 14 is displayed on the display device 6 as described above. When defect information is included in the ultrasonic reception result by the transmission / reception array sensor 14, examples of display forms are as shown in FIGS.

  This is repeated for each feed pitch 29, and the inspection range is ultrasonically inspected. In this way, FIG. 20 shows an example in which the self-propelled inspection device 25 including the transmission / reception array sensor 14 according to the above-described embodiment is applied to the ultrasonic flaw detection work of the H4 weld line 32 of the shroud intermediate cylinder. In this example, the scanning area 28 of the probe scanner 27 and the feed pitch 29 of the self-propelled inspection device 25 are designated and the rectangular scanning is performed once, so that defects on the front surface opening side and the back surface side in the flaw detection area are detected. Detection and sizing are possible regardless of the position of the sensor 14 and the defect. Similarly in the first embodiment described above, ultrasonic waves are transmitted and received from the transmission / reception array sensor 14 to a focusing position where half of the sum of the ultrasonic transmission angle and the ultrasonic reception angle is within 30 degrees. An inspection of a difficult angle range may be performed.

As seen in FIGS. 18 and 19, the defect 22 can be clearly detected and displayed regardless of whether the relative orientation of the defect 22 and the transmission / reception array sensor 14 is orthogonal or parallel. , and supports the transmission and reception array sensor 14 in the rotation axis, or by changing the orientation of the self-propelled vehicle body 33, there is no need to adjust the relative orientation between the defect 22 and the transceiver array sensor 14, the self-propelled vehicle 33 is weld line 32 may be moved. Therefore, an ultrasonic inspection can be performed quickly.

Further, as shown in FIG. 21, an eddy current flaw detection sensor 42 of an eddy current flaw detector (not shown) is installed on the line of the joint surface between the transmission transducer array 15 and the reception transducer array 19 of the transmission / reception array sensor 14. The line on the joint surface between the transmission transducer array 15 and the reception transducer array 19 is the length direction of the element passing through the middle between the transmission transducer array 15 and the reception transducer array 19 as shown in FIG. It means on the extension of the line. In this case, a plurality of eddy current flaw detection sensors 42 may be provided. In the eddy current flaw detection sensor 42, the detection signal from the eddy current flaw detection sensor 42 changes greatly when passing through the crack 22 of the surface defect. The position of the defect crack 22 can be detected. Therefore, the transmission / reception array sensor 14 comes directly above the crack 22 of the surface defect by feeding back the eddy current flaw detection sensor 42 to the monitor of the eddy current flaw detection device or the control means of the self-propelled ultrasonic flaw detection device. Even when the traveling vehicle 33 and the probe scanner 27 are controlled and the traveling vehicle 33 and the probe scanner 27 are moved by remote control, the crack 22 can be sized more reliably.

Further, as shown in FIG. 22, if an eddy current flaw detection sensor 42 is installed between the transmission transducer array 15 and the reception transducer array 19 of the transmission / reception array sensor 14, the length direction of the crack 22 of the surface defect Even if the angle of the transmission / reception array sensor 14 is not perpendicular, the transmission / reception array sensor 14 can be moved directly above the crack 22 of the surface defect, so that the defect can be sized more accurately.

  As described above, according to the self-propelled ultrasonic inspection apparatus, ultrasonic flaw detection can be surely performed even under a condition where the ultrasonic diffraction intensity at the edge of the defect is weak, and the flaw detection range can be obtained by one rectangular scan. It is possible to detect and size the defects on the front surface opening side and the back surface side, and the ultrasonic inspection period of the shroud 41 can be greatly shortened.

  The self-propelled ultrasonic inspection apparatus 25 has one transmission / reception array sensor 14, and the driving axis of the probe scanner 27 is also one axis, and is equipped with a rotating shaft for rotating the transmission / reception array sensor 14 and a plurality of transmission / reception array sensors 14. There is no need to do. Therefore, the self-propelled vehicle 40 that travels while supporting the transmission / reception array sensor 14 and the probe scanner 27 can be miniaturized, and the miniaturization of the self-propelled ultrasonic inspection device 25 that is the traveling body of the ultrasonic inspection device is achieved. it can.

  By achieving the miniaturization of the self-propelled ultrasonic inspection apparatus 25, ultrasonic inspection in a narrower place than before can be performed.

  The present invention is applied to an ultrasonic flaw detector used for nondestructive inspection of products.

1 is an overall view of an ultrasonic flaw detector according to an embodiment of the present invention. The figure which shows the flaw detection method of the weld line by the probe for bevels prescribed | regulated by JEAG4207. The figure which shows the flaw detection method of the weld line by the inspection apparatus carrying the probe for oblique angles. The figure which shows the flaw detection method of the weld line by the inspection apparatus which mounts the probe for oblique angles provided with the rotating shaft in the ultrasonic flaw detection unit. The operation | movement flowchart figure of the ultrasonic flaw detector by the Example of this invention. The timing chart figure of the transmission ultrasonic transducer | vibrator control signal to each vibration element. Transmission ultrasonic wave generation timing chart. FIG. 6 is an exemplary diagram of a defect signal output display example 1 (A scan signal) in the embodiment of the present invention. An explanatory view of the definition of the ultrasonic transmission angle θt and the reception angle θr. Explanatory drawing of the definition of the width / depth / height of the transmission / reception integrated small array sensor, the element width / element length of the ultrasonic transducer, and the insulating material width. FIG. 3 is a structural diagram of a transmission / reception integrated small array sensor. Another structural diagram of a transmission / reception integrated small array sensor. The figure which is the output display example 2 of the defect signal of this invention, and printed on the paper with the printer the image displayed on the display apparatus of an ultrasonic flaw detector. FIG. 10 is an exemplary diagram of a defect signal output display example 3 according to the present invention. The figure which is the output display example 5 of the defect signal of this invention, and printed on the paper with the printer the image represented on the display apparatus of an ultrasonic flaw detector. The figure which shows an example which applied the ultrasonic flaw detector of this invention to defect detection and defect sizing. The figure which shows another example which applied the ultrasonic flaw detector of this invention to defect detection and defect sizing. The figure which shows another example which applied the ultrasonic flaw detector of this invention to defect detection and defect sizing. The figure which shows another example which applied the ultrasonic flaw detector of this invention to defect detection and defect sizing. The figure at the time of applying the self-propelled inspection apparatus provided with the transmission / reception integrated small array sensor of the present invention to the ultrasonic inspection of the H4 weld line of the shroud intermediate cylinder. The figure of alignment with the sensor provided with the sensor for eddy current flaw detection in the transmission / reception integrated small array sensor, and the surface defect in that case. The figure of alignment with another example of the sensor provided with the sensor for eddy current flaw detection in the transmission / reception integrated small array sensor, and the surface defect in that case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Input device, 2 ... Memory, 3 ... Ultrasonic control apparatus, 4 ... Information processing apparatus, 5 ... I / O, 6 ... Display apparatus, 7 ... Transmission ultrasonic transducer control apparatus, 8 ... Reception signal processing apparatus, DESCRIPTION OF SYMBOLS 9 ... Transmission side amplifier control apparatus, 10 ... Reception side amplifier control apparatus, 11 ... Transmission side amplifier, 12 ... Reception side amplifier, 14 ... Transmission / reception integrated small array sensor, 15 ... Transmission transducer array, 16 ... Ultrasound, 17 ... Focusing point, 18 ... Diffraction wave, 19 ... Receiving transducer array, 20 ... Ultrasonic reception signal (electric signal), 21 ... Material to be inspected, 22 ... Defect, 25 ... Self-propelled ultrasonic inspection device, 26 ... Ultra Sonic flaw detection unit, 27 ... probe scanner, 28 ... scanning range, 29 ... feed pitch, 30 ... rotating shaft, 31 ... probe, 32 ... weld line, 33 ... vehicle body, 34 ... travel motor, 34 '... thruster , 35 ... wheel, 36 ... drive shaft, 37 ... mobile frame 38 ... scanning motor, 39 ... probe holder, 40 ... running vehicle, 41 ... shroud, 42 ... eddy current sensor, 100 ... casing, 101
DESCRIPTION OF SYMBOLS ... Epoxy resin board, 102 ... Resin, 103 ... Sound insulation material, 104 ... Sound absorption material, 122 ... Ultrasonic flaw detector main body, 123 ... Signal cable.

Claims (16)

A transmission transducer array in which a plurality of transducer elements for transmitting ultrasonic waves are arranged and a reception transducer array in which a plurality of transducer elements for receiving ultrasonic waves are arranged are coupled in series in the arrangement direction of the plurality of elements. The transmit / receive array sensor
Focuses the respective ultrasound half of the sum is transmitted from the moving element vibration for the transmission of each focusing position is within 30 degrees of the ultrasonic transmission angle and the ultrasonic reception angle, originating from the moving element vibration for the transmission A control device that focuses and scans the focused position of each of the ultrasonic waves from the center of the transmitting transducer array and the receiving transducer array in the direction of the deep layer in the inspection target material; and
Generated by the synthesizing unit, and synthesizing means for synthesizing ultrasonic information diffracted in the inspection target material received by the receiving vibration element as flaw detection information based on a focused position of the transmission ultrasonic wave. An ultrasonic inspection apparatus having display means for displaying flaw detection information. According to claim 1, wherein the focusing position of each ultrasonic wave transmitted from the transmitting vibration element, is focused at a constant distance from the center of the receiving transducer columns and the transmission transducer column, and the arc of the angle An ultrasonic inspection apparatus comprising a control device that scans in a direction.   3. The method according to claim 1, wherein the transducer elements of each transducer array have a width of 0.1 mm to 2.0 mm, and the adjacent transducer elements in each transducer array are mutually connected. The ultrasonic inspection apparatus is arranged with a gap of 0.05 mm to 0.20 mm.   4. The ultrasonic inspection apparatus according to claim 1, wherein the control device that focuses each of the ultrasonic waves includes means for electronically changing a focusing position that focuses each of the ultrasonic waves. 5.   5. The ultrasonic inspection apparatus according to claim 4, further comprising first amplification degree control means for changing an amplification degree of a signal given to the transmitting vibration element according to the focusing position.   6. The ultrasonic inspection apparatus according to claim 5, further comprising second amplification degree control means for changing an amplification degree of a signal output from the receiving vibration element in accordance with the focusing position. In any one of claims 1 to 6, the element length of the between the transmitting transducer rows and the receiving transducer column, or the transducers constituting the receiving transducer columns and said transmission oscillator column An ultrasonic inspection apparatus comprising an eddy current flaw detection sensor at a position in a direction extending in the direction. In any one of claims 1 to 6, comprising a scanning means for mechanically scanning said transceiver array sensor, and a free-running means for self-propelled surface of the inspection target material supporting said scanning means Ultrasonic inspection device. 8. The ultrasonic inspection apparatus according to claim 7, further comprising: a scanning unit that mechanically scans the transmission / reception array sensor; and a self-running unit that supports the scanning unit and self-runs the surface of the inspection target material. 9. The scanning means according to claim 8, further comprising a mechanism capable of reciprocally scanning the transmission / reception array sensor in one direction along the surface of the material to be inspected, wherein the one direction is orthogonal to the traveling direction of the self-running means; An ultrasonic inspection apparatus attached to the self-propelled means. 10. The scanning means according to claim 9, further comprising a mechanism capable of reciprocally scanning the transmission / reception array sensor in one direction along the surface of the material to be inspected, wherein the one direction is perpendicular to the traveling direction of the self-running means; An ultrasonic inspection apparatus attached to the self-propelled means. The ultrasonic wave received by the receiving vibration element according to claim 10, wherein the transmission / reception array sensor is caused to pass over a welding line by the reciprocal scanning mechanism and mechanically scanned in a direction orthogonal to the welding line. An ultrasonic inspection apparatus comprising an apparatus for acquiring information on a welding boundary from flaw detection information synthesized based on a focused position of transmission ultrasonic waves and detecting a position of the self-propelled means from a weld line. The ultrasonic wave received by the receiving vibration element according to claim 11, wherein the transmission / reception array sensor is passed over a welding line by the reciprocating scanning mechanism and mechanically scanned in a direction orthogonal to the welding line. An ultrasonic inspection apparatus comprising an apparatus for acquiring information on a welding boundary from flaw detection information synthesized based on a focused position of transmission ultrasonic waves and detecting a position of the self-propelled means from a weld line. 14. The eddy current according to claim 13, wherein the transmission / reception array sensor is caused to pass over a surface defect whose existence has been confirmed in advance by the mechanism capable of reciprocating scanning, and is mechanically scanned in a direction perpendicular to the surface defect. It has a position detection device that acquires information on the position of a surface defect from a signal received by a sensor for flaw detection, and has a device that installs the transmission / reception array sensor immediately above the surface defect from the acquired position information. Sonographic equipment. A transmission transducer array in which a plurality of transducer elements for transmitting ultrasonic waves are arranged and a reception transducer array in which a plurality of transducer elements for receiving ultrasonic waves are arranged are coupled in series in the arrangement direction of the plurality of elements. The transmission / reception array sensor is mounted on a self-propelled means that self-propells along the weld line via a scanning means, and the self-propelled means repeats traveling and stopping along the weld line, and when the self-propelled means is stopped, The transmission / reception array sensor is passed over the welding line and mechanically scanned in a direction perpendicular to the welding line, and half of the sum of the ultrasonic transmission angle and the ultrasonic reception angle of the transmission / reception array sensor is within 30 degrees. The inspection target material received by the receiving vibration element by focusing each ultrasonic wave transmitted from each of the transmission vibration elements at a focusing position in the direction of the deep layer in the inspection target material to which the welding line is applied. Diffracted within Ultrasonic inspection method so as to synthesize as inspection information based on the information of the sound waves to the focusing position of the transmission ultrasonic waves. 16. The transmission / reception array sensor according to claim 15, wherein the transmission / reception array sensor is passed over a surface defect whose presence has been confirmed in advance by a mechanism capable of reciprocating scanning in one direction along the surface of the material to be inspected, and in a direction perpendicular to the surface defect. Mechanically scanned between the transmission transducer array and the reception transducer array, or in the element length direction of each transducer constituting the transmission transducer array and the reception transducer array, and between Information on the position of the surface defect is obtained from the signal received by the eddy current flaw detection sensor located in the extension direction, and the transmitting / receiving array sensor is installed immediately above the surface defect by the self-propelled means from the obtained position information. An ultrasonic inspection method characterized by ultrasonic flaw detection.

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